The present invention relates to a tank levek meter, particularly for measuring contents of a fuel tank of a motor vehicle by means of sound waves propagating through a sound conducting member extending from the bottom to a top region of a tank. It is known to measure the liquid level and thus heads of the liquid by means of a sound receiver, a sound transmitter and a sound propagating body. However, these known measuring arrangements are based on sonic depth finding processes or reflection sounding at an interface. These known liquid level indicators however are applicable only with difficulties for fuel tanks of a motor vehicle because such tanks have normally irregular configuration. In addition, the sonar based devices are expensive and complicated in structure, detect the reflected echoes inaccurately and are susceptible to interferences.